1.02 2007/2 SCREW THREAD TYPES AND THEIR USES Sketch Thread Denominations Usual use Misc. information M MJ Standard metric thread Aerospace
1.02 2007/2
SCREW THREAD TYPES AND THEIR USES Sketch
Thread Denominations M MJ UN, UNC, UNF, UNEF, UNS UNJ, UNJC, UNJF, UNJEF NPSI, NPSM, NPSL, NPSH, NPSF, NPSI
G, BSP, Rp, BSPP
Usual use Standard metric thread Aerospace Standard ISO Inch threads
Misc. information Pitch in mm
Pitch in T.P.I. USA, UK and Canada Pitch in T.P.I. UK Pipe fitting with straight threads. Pitch in T.P.I When pressure-tight joints are not USA, UK and Canada made on the thread Pipe fitting with straight threads. When pressure-tight joints are not Pitch in T.P.I. made on the thread Only in 28, 19, 14 and 11 TPI Pitch in T.P.I. Planned to be made redundant
W, BSW, WG, BSF, WFG
Pitch in mm
30
O
Tr
29
O
ACME, STUB ACME
R, Rc, BSPT
NPT, NPTR, NPTF
When movement is transferred to rails
Pipe fittings with a tapered thread. When pressure-tight joints are made on the thread. Pipe fittings with a tapered thread. When pressure-tight joints are made on the thread
Pitch in T.P.I. USA, UK and Canada Pitch in T.P.I. R is an external tapered thread. Rc is an internal tapered thread. Rp is a straight internal thread. Only in 28, 19, 14 and 11 TPI
Pitch in i T.P.I. Only in 27, 18, 14, 11½ and 8 TPI Pitch in T.P.I. Flank angles are not equal and vary depending on use and material.
Butt, Buttress
Hydraulics, plastics, wood etc.
Rd
Dairy fittings and accessories
Pitch in T.P.I. Only in 10,8, 6 and 4 TPI
Pg
Electronics
Pitch in T.P.I. Only in 20, 18 and 16 TPI
There are many other screw thread types. We welcome suggestions for updates to this page.
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